a) Field of the Invention
The invention is directed to a snap fastening for fast mounting of fittings, such as socket wrench latches, swivel lever latches, hinge parts, in openings in a thin wall, comprising a head part which is to be arranged on one, outer side of the thin wall and which overlaps the outer rim of the opening, and a body part which proceeds from the head part and projects through the opening in the mounted position, and holding elements which project from the body part and are flexible in direction of the outer surface of the body part, the free end of these holding elements being provided with a first inclined surface such that the holding elements (36) can be pushed back in a spring-loaded manner by the opening edge and with a second inclined surface for supporting the body part without play on the rim of the opening of the other, inner side of the thin wall, which second inclined surface is substantially perpendicular to the first inclined surface.
b) Description of the Related Art
U.S. Pat. No. 5,435,159 discloses a snap fastening for quick mounting of a lock housing which can be arranged, for example, in a round opening in a thin wall. The housing which is intended for a sash latch comprises a head part, namely, a flange, which is to be arranged on one, outer side of the thin wall and which overlaps the outer rim of the opening, a body part which projects through the opening in the mounted position proceeds from this head part, and tongue elements which are flexible in the direction of the outer surface of the body part project from the body part and have an inclined surface at their free ends for supporting the body part without play on the rim of the opening of the other, inner side of the thin wall. The holding force of the holding elements or tongue elements which are formed integral with the body part depends upon their spring tension, which depends upon the plastic material that is used, and therefore this holding force cannot be made as high as might be desired.
EP 0258491 A1 discloses a similar construction by which a lock cylinder can be fastened in thin-walled doors, drawers or the like by means of a plastic housing which receives the lock cylinder and which forms holding tongues. By means of inclined surfaces at the ends of the tongues it is possible to adapt in a desirable manner to commonly occurring variations of the structural component parts to be locked. It is also stated in column 9 of the reference that the springing tongues can no longer deflect inward after the lock cylinder is mounted in the housing. This has the disadvantage that a very particular design, namely, a round housing with a lock cylinder inserted therein, must be provided in order to allow the tongues to be locked in this way after mounting.